Background
Single-arm prospective study (Cheng 2003). N=125 consecutive adults with newly diagnosed ITP, platelet <20×10⁷/L or <50×10⁷/L with significant bleeding; enrolled Jan 1997 - Dec 2000, Chinese University of Hong Kong. Evaluated 4-day high-dose dexamethasone (HD-Dex) as initial therapy vs the prior standard of prolonged prednisone (1 mg/kg × 4-6 wk + slow taper).
Interventions and follow up
Treatment: High-dose dexamethasone 40 mg PO daily × 4 days as initial therapy for newly diagnosed ITP; no further therapy unless relapse
Primary endpoint: Initial response (platelet ≥50×10⁷/L by day 10) and sustained response (platelet >50×10⁷/L at 6 mo)
mFollow up: 6 mo
Primary endpoint: Initial response (platelet ≥50×10⁷/L by day 10) and sustained response (platelet >50×10⁷/L at 6 mo)
mFollow up: 6 mo
Results
Initial response (platelet ≥50×10⁷/L by day 10): 85% (106/125); mean platelet 101,400/µL by wk 1
Sustained response at 6 mo: 50% of initial responders (53/106) = 42% of all enrolled
Relapse timing: 94% of relapses within 3 mo of treatment
Predictor of relapse: platelet <90×10⁷/L on day 10 associated with high relapse risk
Sustained response at 6 mo: 50% of initial responders (53/106) = 42% of all enrolled
Relapse timing: 94% of relapses within 3 mo of treatment
Predictor of relapse: platelet <90×10⁷/L on day 10 associated with high relapse risk
Adverse events
Overall tolerability: generally well tolerated; no major grade ≥3 AEs related to the 4-day course reported
Steroid effects: insomnia, mood changes, hyperglycemia — transient, resolved after the 4-day course
Cushingoid effects: none, given short-course design
Steroid effects: insomnia, mood changes, hyperglycemia — transient, resolved after the 4-day course
Cushingoid effects: none, given short-course design
Conclusions
A 4-day course of oral high-dose dexamethasone (40 mg/day) achieves initial platelet response in 85% of adults with newly diagnosed ITP and sustained response at 6 mo in ~42% — comparable to or better than prolonged prednisone, with far lower cumulative steroid exposure.
Key Limitations
Single-center single-arm design with no randomized comparison to prednisone; modest 6-mo durability (~42% sustained). Short follow-up; relapses common within 3 mo. Generalizability beyond a single Hong Kong cohort untested.
Clinical Context
Helped establish short-course high-dose dexamethasone as a first-line corticosteroid option in newly diagnosed adult ITP. ASH ITP guidelines now favor a short steroid course (dexamethasone or prednisone) over prolonged prednisone for limiting cumulative toxicity, with TPO-RAs/rituximab reserved second-line.